A dark-green, bullet shaped (7/8″ diameter by 1-3/4″ thickness) cone, made of  40 grit, coarse Cratex.  This tough, resilient, rubberized abrasive utilizes silicon carbide as the abrasive grain in a standard bond of premium grade, oil-resistant chemical rubber. Its unique cushioned action allows the abrasive grains to cut freely, smoothly and softly without gouging or digging into the work surface. Ideal for work on jewelry, plastic parts, small castings and models. 1/4″ arbor hole with a threaded insert to accept Cratex mandrel 1341 – sold separately.  Maximum safe operating speed: 20,000rpm with a 1/2” overhang or less (exposed mandrel length). For each additional 1/4” of overhang the Maximum Safe Speed is decreased by at least 20%. Best results are usually obtained at 30% to 80% of Maximum Safe Speed. Use a light work pressure. Made in Mexico.